Ore-concentrating table.



' PATENTED JUNE 28, 1904.

G. A. OVERSTROM.

ORE GONGENTRATING TABLE.

APPLICATION FILED JULY 30. 1903.

NO MODEL.

UNITED STATES Patented June 28, 1904.

PATENT OFFICE.

GUSTAVE A. OVERSTROM, OF CHICAGO, ILLINOIS, ASSIGNOR TO OVER- STROM CONCENTRATOR COMPANY, OF BUTTE, MONTANA, A CORPO- RATION OF MONTANA.

ORE-CQNCENTRATING TABLE.

SPECIFICATION forming part of Letters Patent No. 763,787, dated June 28, 1904. Application filed July 30, 1903. Serial No. 167,532. (No model.)

To all whom it may concern:

Be it known thatI, GUs'rAvE A. OVERSTROM, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illithe finer particles of mineral values are permitted to settle to enable the same to be separated and recovered.

Other objects of the invention will appear more fully hereinafter.

The invention consists, substantially, in the construction, combination, location, and relative arrangement of parts, all as will be more fully hereinafter set forth, as shown in the accompanying drawings, and finally pointed out in the appended claims.

Referring to the accompanying drawings,

and to the various views and reference-signs.

appearing thereon, Figure l is a View in plan of an ore-concentrating table embodying the principles of my invention. Fig. 2 is a section on the line 2 2 of Fig. 1 looking in the direction of the arrows. Fig. 3 is a detached detail View in side elevation of one of the long riflles and constructed in accordance with the principles of my invention. Fig. 4 is a view similar to Fig. 3, showing a shorter riflie employed lower down on the surface of the table or toward thetailings-discharge edge thereof and embodying the principles of my invention. Fig. 5 is a broken detail view in section on the line 5 5, Fig. 1, looking in the direction of the arrows. Figs. 6 and 7 are detached detail views similar to Figs. 3 and 4, showing modified forms of rifiles embraced within the spirit and scope of my invention.

The same part is designated by the same reference-sign wherever it occurs throughout the several views.

In the art of ore-concentration it has been customary to employ concentrating-tables upon which the crushed ore is supplied along With feed-water, such table being slightly in acting thereon in intersecting lines, with theresult that a tendency is created to carry the mineral particles in the direction of the component of these forces. In order to prevent the mineral values from being carried over the lower or tailings-discharge edge of the table along with the tailings feed and wash water and to enable or permit the mineral values to be caught and to settle down upon the tablesurface, it has been customary to provide riffies upon the table-surface arranged to extend generally in the line of the reciprocatory movements imparted to the table, the riflies forming a protection against the liability of the mineral particles being carried across the surface of the table and over obstructions which permit the mineral values to settle down in the troughs formed by the riffles, and when once caught in this manner by a riffie such mineral particles are advanced by the reciprocatory movements in the direction of the length of the table, finally emerging from the troughs formed by the riflies upon a smooth portion or surface adjacent to the foot end of the table and over which washwater flows and is finally delivered in concentrate form over the foot end of the table. In order to gradually withdraw the protection aflorded by the obstructing riifles, it has been a common practice to taper the riflies in the It has also been customary direction of the length thereof from the head end of the table toward the foot end, and thus enabling the transversely-flowing wash-water to gradually remove the tailings, silica, shale, rock, gangue, and the like and accomplishing the concentration of the mineral values. This practice results in a form and construction of,

rifle which is highest or extends to a greater height above the surface of the table at the head end of the table and gradually diminishing in height or tapering to the foot end of the table. This arrangement, however, has been found in practice to be open to objections. The fine mineral particles delivered along with the feed of material and feedwater are carried to a considerable distance while being held in suspension in the feedwater. If, therefore, this feed-water carrying the fine mineral particles in suspension is permitted to flow when delivered to the table over the empty rifle-spaces toward the tailings-discharge edge of the table, or rather over rifle-spaces filled with water, they are kept or retained in suspension from rifle to rifle without being permitted to settle down sufficiently to be caught by the rifle by reason of the agitation of the water, due largely to the reciprocatory movements of the table, such fine particles of mineral being finally discharged, together with the dirty feed-water,

over the tailings-discharge edge or side of the table nearest the head endof the table, and hence are lost. In order to avoid this source of loss, it is desirable to provide a bed of silica at the feed-in end of the table, as the finer mineral particles are more readily caught by a loose bed'of silica andare permitted to settle more quickly to such bed of silica, and, moreover, the fiow of the dirty water over a bed of silica is more even and more free from agitation than is the case of such water flowing over empty rifle-spaces, thereby allowing the mineral particles to more readily settle between the coarser particles of silica, and hence out of danger of being maintained in suspension'in the water or of being washed or carried over the lower side or edge of the table along with the tailings or dirty feedwater. However, with a rifled table wherein the rifles are of greatest height at the feed-in end of the table it is impossible to secure an efiicient spreading out of the bed of silica, and an eflcient even spreading out of this bed is an exceedingly desirable object to be attained. Therefore it is among the special purposes of my present invention to provide such an arrangement of rifles in an orcconcentrating table as will permit me to secure an efiicient spread of the feed over the table-surface at the feed-in end or head-m0- tion end of the table. In accordance with the principles of my invention, therefore, I propose to employ rifles which are of increasing height for a portion of the length thereof from the head end of the table toward the foot end thereof, and for another portion of the length of such rifles I propose to gradually decrease the height of such rifles. In other words, I propose to employ in practical effect a rifle tapered in both directions from a point intermediate the ends thereof, so that the highest point or greatest height of the rifle above the table-surface will not be at the head end of the table, but some distance therefrom toward the foot end of the table. This result may be secured either by gradually tapering the rifle from such intermediate pointtoward both the head and foot end thereof and also by forming the rifle in steps of increasing heights from the head end of the table for a portion of the length of the rifle. I do not desire, therefore, that my invention shall be limited in this respect, and when I refer to a rifle as being tapered I desire to be understood as including thereby not only a gradual taper of the rifle, but also the step form of construction of rifle, as will be more fully hereinafter explained.

It is usual to supply the crushed ore and feed-water to a feed-box mounted upon or employed in connection with the concentrating-table, the material being deposited from such feed -box upon the concentrating-table through holes or openings formed in the bottom or sides of the feed-box, an equal quantity of the feed being deposited upon the table-surface through the feed holes or openings. In order to secure the best results, therefore, a definite relation should exist between the degreeof taper of the rifle at the head end of the table and the number of feed holes or openings in the feed-box. For instance, if the feed-box has eight feed holes or openings it is obvious that in order to secure the desired results of an efficient spread of the material over the table-surface at the head end thereof in accordance with the principles of my invention the rifles are not required to extend as high above the table-surface at a'point opposite the first of the feed holes or openings in the feed-box, counting from the head end 'of the table, as at a point opposite the second feed hole or opening, because only the amount of mineral contained in the crushed ore delivered to the table through the first opening is required to be taken care of at a point opposite such first opening,whereas this amount of feed isaugmented by the amount delivered to the table through the second opening, and hence the height of the rifles opposite the various succeeding feed holes or openings of the feed-box must be correspondingly increased, assuming that an equal amount of feed is supplied to the table-surface through each slot or opening in the feed-box. Thus if in practice the amount of feed supplied through the first feed opening or hole requires at a point opposite thereto a rifle one thirtysecond of an inch in height then opposite the second feed hole or opening the height of the rifle should be just double, or two thirty-seconds of an inch, and opposite the third three thirty-seconds of an inch, and so on for as many feed holes or openings, counting from the head end of the table, as the feed-box may have. Therefore it is within the spirit and scope of my invention'not only to taper the rifles in. opposite directions, but to arrange the backward taper at the feed-in end of the table in a definite relation to the feedin order to secure the best results.

In the accompanying drawings I have shown an ore-concentrating table embodying in its construction features enabling me to secure the advantages above noted and wherein reference-sign A designates the feed-box and B the wash-water-supply pipe. The feed-box A is located, preferably, along the upper edge of the table and in proximity to the head end C of the table, while the wash-water-supply pipe B extends along the upper edge of the table from the feed-box to the lower end D of the table. The rifles are indicated generally by reference-sign E and are arranged to extend from the head end C of the table toward the foot end D thereof and in very nearly parallel relation with respect to each other. I prefer to slightly flare or separate the rifles at the head end of the table, so as to secure a greater space between the rifles at this point to enable the feed to be more'evenly spread out when received upon the table and over a more extensive surface or area. Each rifle is provided with a double taper, the tapered portion of each rifle being indicated by reference-signs F and G, the tapered surface G beginning at the point H and extending therefrom to the extreme head end of the rifle, while the taper F begins at the point J and extends to the extreme foot end of the rifle in the forms of my invention shown in Figs. 1, 2, 3, and 4, leaving a portion of the rifle between the points H and J of equal height above the surface of the table. If desired, however, and included within the spirit and scope of my invention, the oppositelytapering surfaces F G of the rifle E may meet in an apex H, thereby omitting the portion extending between the points H and J. This form of rifle is illustrated in Fig. 6. In accordance with the spirit and scope of my invention the degree of taper of the surface G of each rifle, especially that portion of the rifles lying directly opposite the feed-box, should bear a definite relation to the feed, as

, above explainedl For instance, in the particular case illustrated, to which, however, my invention is not to be limited or restricted, the feed-box is provided with eight feed openings or holes marked, respectively, a, b, c, d, e, f, g, and It, and since an equal amount of materialis fed to the table-surface through each of these feed holes or openings it will be apparent that the portions of the rifles lying directly opposite the feed-opening a will be required to take care of only the amount of feed supplied through the feed hole or opening a. Therefore at this point the rifles should be of the least height above the tablesurface. The same amount of feed is supplied to the table through the openingb as through the opening a. Therefore to take care of this additional amount of feed the portion of the rifles lying directly opposite feed hole or opening 7) should be of greater height than the portions of the rifles lying opposite the feed hole or opening a. If. therefore, the rifles are one thirty-second of an inch high opposite feed-hole a, they should be two thirty-seconds of an inch high OpPOSite hole 6, three thirty-seconds of an inch high opposite feed-hole o, and so on for as many feed holes or openings as are provided in the feed-box. As above explained, this same idea may be accomplished in providing the rifles with steps. In Fig. 7 I have shown a rifle E having the steps a Z) 0 d e f g it instead of tapering the rifles; but, as above explained, this form of rifle is designed to be included within the generic expression of taper in describing and claiming this feature of my invention.

At their foot ends the rifles terminate, preferably, at right angles to a line transverse of the table and upon a smooth or unrifled portion or surface M of the table, (see Fig. 1,) the concentrates delivering over the linoleum apron N at the extreme foot end of the table, any middlings that may be produced being delivered over a short raised rib A, arranged at the lower side or edge of the table at its extreme lower corner or between the points marked 0 and P, while the tailings, sand, silica, or the like are delivered over the tailings-discharge edge K of the table between the points marked 0 and Q.

So far as the work of spreading the feed over the table-surface is concerned only the portion of the rifles lying directly opposite to the feed-box need be tapered backwardly or towardthe head end of the table, and in Fig. 1 I have indicated by the dotted lines R and S the line of-the beginning of the backward as well as the line of the beginning of the forward taper of the rifles.

Reciprocations may be table in any suitable or convenient manner. I have indicated at W an operative mechanism for accomplishing this result; but I do not desire to be limited or restricted to the specific construction shown, as any form of headmotion mechanism may be employed.

The operation of an ore-concentrating table embodying the principles of my invention will be readily understood; but for the sake of clearness I will briefly set forth the same.

imparted to the The feed, along with the feed-water, is supplied to the feed-box and is delivered thence upon the table-surface at its upper corner through the feed holes or openings (0 b c, &c., through the feed-box. The material becomes quickly spread out evenly over the surface of the table at the head end of the table, and under the combined influence of the reciprocatory movements imparted to the table and the transversely-flowing feed and wash water and inclination of the table the work of separation commences. The mineral values being heavier than the silica, gangue, shale, rock,

and the like settle down through the bed or mass of sand, silica, or the like and in between the rifles, and any of the finer mineral particles held in suspension in the feed-water are permitted to settle down to the surface of the bed of silica by reason of the fact that the water is not so violently agitated when flowing over such bed and over an extended area thereof produced by the backwardly-tapering portions G of the rifles, and hence I avoid the danger of such finer particles of mineral being carried or washed over the tailings-discharge edge of the table along with the dirty feed-water, sufficient opportunity being given to enable or permit such finer mineral particles to settle down. As the operation of the machine continues, the mineral values, along with a portion of the sand, silica, rock, and the like, are advanced in the direction of the length of the rifles and under the protection aiforded by the rifles as obstructions until they gain the table-surface below or toward the foot end of the table from the feedbox. Here the wash-water plays transversely across the table-surface, and hence by reason of the gradual withdrawal of the protection afforded by the rifles, due to the forwardlytapering surfaces F of the rifles, a gradual and eventually a complete separation of the mineral values from the dirt, silica, and the like is effected, the latter being washed transversely across the table and over the tailingsdischarge edge of the table with the washwater, the mineral values being finally delivered upon the smooth unrifled suface M of the table, where the final separation due to the action of the wash-water is accomplished, the concentrates being finally delivered over the foot end D of the table.

From the foregoing description it will be seen that I provide an exceedingly simple and efficient construction of ore-concentrating table wherein an even distribution of the feed over a wide area of table-surface at a point where the feed is delivered to the table is effected and wherein every opportunity is permitted the mineral values held in suspension in the feed-water or otherwise to settle or gravitate to the table-surface or to the protection of the rifles or the coarser particles of sand, rock, or the like.

I desire it to be understood thatmanyvaria tions and changes in the details of construction and arrangement would readily occur to persons skilled in the art and still fall within the spirit and scope of my invention. I do not desire, therefore, to be limited or restricted to the exact details shown and described; but,

Having now set forth the object and nature of my invention and various constructions embodying the principles thereof, what I claim as new and useful and of my own invention,

and desire to secure by Letters Patent, is'

1. The combination with an ore-concentratingtable and a feed-box, of rifles arranged on the upper surface of the table, that portion of the'rifles lying opposite to and to an extent equal to the length of the feed-box increasing in height from the head end toward the foot end thereof, as and for the purpose set forth.

2. The combination with an ore-concentrat ing table, of a feed-box having feed openings or holes, and rifles arranged upon the upper surface of the table, that portion of the rifles lying opposite the feed -box increasing in height from a point opposite the feed hole or opening of the feed-box nearest the end of the table, said increase in height being in proportion to the number of feed holes or openings in the feed-box opposite which the rifles lie.

3. The combination with an ore-concentrating table, of a feed-box having feed holes or openings therein delivering upon such table, and rifles arranged upon the upper surface of said table, the portion of the rifles lying opposite the feed-box increasing in height, said rifles tapering or decreasing in height toward their other ends, as and for the purpose set forth. 7

4. The combination with an ore-concentrating table, means for reciprocating the same, and means for supplying the material to the table, of rifles arranged upon the upper surface of said table and extending generally in the direction of reciprocations imparted to the table, that portion of said rifles lying opposite the feed being of increasing height from the head toward the foot end of the table, the remaining portion of such rifles being of decreasing height. V

5. The combination with an ore-concentrating table and means for imparting reciprocatory movements thereto, of a feed-box arranged adjacent to the head of the table, said table having an unrifled surface at its foot end, said rifles being of increasing height from the head end of the table for the portion of the length thereof corresponding to V material upon the surface of said table, and In Witness whereof I have hereunto set my riflles arranged upon the upper surface of hand, this 24th day of July, 1903, in the pres- [0 said tablie, said riffies bleingil slighltly spread ence of the subscribing Witnesses.

apart an of increasing eig t in t e portion of the length thereof lying opposite to and GUSTAVE OVERSTROM' corresponding to the length of said feed-box Witnesses:

and decreasing height toward the opposite CHAS. H. SEEM,

ends thereof, as and for the purpose set forth. S. E. DARB. 

